The lumpy-idling 101 LSA cam churned out an average of 484.0 hp at 6,100 rpm with 493.9 lb-ft of torque at 4,400 rpm. You must log in or register to reply here. If that accessory still does not assist the cam in producing enough vacuum, then as a last resort you can use a vacuum pump. Average power was also down, but the engine pulled ahead of the 101 cam at 5,400 rpm, picking up 6.5 hp at peak. 112 will have a smoother idle, a wider power band, and will work better with fuel injection. The tightest LSA (101) was worth 21.5 lb-ft of torque and a much broader powerbandat the cost of much lower idle vacuum, which would make it more temperamental in a street car. When you don't have any overlap, you can't have any wave tuning. Topping the short-block was a set of Chevrolet Performance CNC LS3 heads from Gandrud Chevrolet. not exactly true, Ive seen custom grinds that are on 108 lca, smooth idle, high vacuum an even able to run efi, usually on an off the shelf cam it is true. The #1 intake lobe centerline is usually between 100 such as 290 @.050? The intake air control valve (IAC), which regulates idle speed, also has to work overtime and often attempts to "catch" the idle, but usually shoots high or low. 106 LSA: As the 106 LSA is a tighter LSA, it fails to generate maximum power. Simply put, both 106 and 110 lobe separation angles have many advantages and disadvantages. An RV or towing camshaft, which is considered a mild performance or an economy cam, will often have a narrower LSA, between 112 and 114 degrees. The 402 was run with a FAST LSXR LS3 intake and matching 102mm throttle body along with stock LS3 rockers, a Holley HP management system and 7.4-inch hardened pushrods (from Comp Cams). I've seen a few comments in threads on here that have said things like "going to the 112LC from the 108LC gives 4lbft more torque at the bottom and 2bhp more at the top" yet this would seem to go against what webcam say on. Whatever you do, stay under 270 advertised duration and shoot for a 110 lobe separation. (ICL + ECL) / 2 = LOBE SEPARATION ANGLE (LSA) LSA is a RESULT of the PROPER events. This was science at work, and with data in tow, it was time to crunch the numbers and find out what was going on. Typically, narrower lobe separation develops peak torque at lower rpm and widening the separation tends to build peak torque higher in the rpm range. A wider lobe separation angle can often provide more power, but it can also lead to more wear on the engine. The custom cams we selected all featured 0.624-inch lift (both intake and exhaust) and a 232/242-degree duration split. Supercharged and nitrous race engines typically benefit from a wider LSA because they dont require as much overlap for exhaust scavenging as does the naturally aspirated engine, continues Bolander. 2.1.2.4.2 Side-lobe suppression shall be provided in accordance with the provisions of 3.1.2.1.5.2.1 on all Mode S-only all-call interrogations. Because the lobes are closer together on the 101 LSA cam, the intake closing point is advanced (closes earlier) and the piston has more time to build compressionexactly what the gauge showed. General topics - 76 LA built, CA car with m20. But there is a drawback of higher cylinder pressure: higher cylinder pressure may sometimes lead to piston or piston ring problems. 106 LSA: At this LSA, the car machine has to confront the reduction of idle vacuum rate quite often. While a cam with a 108 lobe center will idle rougher. The only reason I . Call for details with your specific combination. At a lower LSA, the engine reaches the peak of the torque earlier than the standard time but generates a lower RPM.On the contrary, at a higher LSA, the engine reaches the peak torque at a higher resistance level and generates a bulk number of RPM. But, after comparing these two LSA based on a few mechanical aspects, such as maximum Torque, RPM, powerband, oil consumption, and many more, you will find the 106 LSA with better performance output. by flat4racer17 Mon May 12, 2003 1:40 pm, Post Only once the intake valve has closed can compression begin to build. The absence of engine knocking ensures that your car engine is reasonably combusting the fuel. However, a cam with 108 will only pull 12-16", which is not enough for power assisted accessories. The center of those 2 events is the LOBE CENTERLINE (ECL). Comparison Table Between 106 Vs 110 Lobe Separation Angle. Enter lobe separation angle. 112-110 Deg. Before we all start suffering from separation anxiety, we need to understand what lobe separation angle actually is and then how it affects your engine. The introduction of Lunati'snew Bootleggerhydraulic series - with its wicked 108-degree lobe-separation angle, fast opening profile and plenty of area under the lift curve - will serve only to fuel the flames on this heated bench-racing topic. We will safeguard your e-mail and only send content you request. To establish the position of each lobe, the traditional reference point is where the lobes reach max lift. Builds More High-RPM Power Increase Piston-Intake Valve Clearance Decrease Piston-Exhaust Valve Clearance EFFECTS OF CHANGING LOBE SEPERATION ANGLE (LSA) Tighten (smaller LSA number) Moves Torque to Lower RPM Increases Maximum Torque Narrow Power band Builds Higher Cylinder Pressure Increase Chance of Engine Knock Increase Cranking Compression Well, there can be different reasons for this problem. Alternatively, if you are running a bigger camshaft to gain maximum top-end power, cam makers often suggest reducing the lobe separation angle to recover power lost in the lower rev range.. Thats just the way the customer wants to roll, and engine builders find its easy to deliver such a powerplant. And better gas mileage. The takeaway from this test is camshaft LSA is a double-edged sword. I believe you have got the idea of what you were seeking. Come join the discussion about restoration, builds, performance, modifications, classifieds, troubleshooting, maintenance, and more! It affects the amount of valve overlap; that is the brief period of time when both the intake and exhaust valves are open. But this is not the only reason. Brul spun the engine over with the dyno's starters and recorded 185 psi of cranking compression. 108 versus 110 will drive the power band down. Nothing makes mouths drop like a car that sounds and looks like it can't keep it self still! Save my name, email, and website in this browser for the next time I comment. On a naturally aspirated engine, the lobe separation angle has an effect on whether the engine reaches peak torque a little earlier or later in the rpm range. I think that cam had 110 lobe sep. Im loking at a summit cam with close to the same lift and duration #s but 114 lobe sep. Idle vacuum showed a considerable spike to 14.7 in-Hg, likely the difference between being able to run power brakes and a mandatory leg workout. On the cranking. 114LSA +4 puts the intake centerline at 110 degrees before top dead center. The Wastegate works by releasing the pressure built inside, Read More What Are The Wastegate Stuck Open Symptoms?Continue, Oops! The reduced rate of the EGR effect lowers oxygen circulation in the engines combustion chamber. Good cam for a lower rpm street engine. I don't know about 13 to one but I have seen 12 to one on a 350 chev in hot rod article, BUT the guy soft petals around on the street with no full throttle use and puts racing gas in at the track. It's the scavenging effect of the high velocity exhaust gases rushing out that pulls the fresh fuel/air charge into the chamber. The wider lobe separation angle closes the intake valve later and reduces cylinder pressure, so that is where it's detonation resistance comes from. Nitrous engines, which make plenty of power and torque, often run wide lobe separation angles to moderate cylinder pressures and temperatures. I will be running an Edelbrock Performer RPM, with a Quick Fuel 750cfm with a screw adjustable vacuum secondary; it's called the Pro-vac. The result sounded wonderful, but it didnt rev as enthusiastically and it made 30 less horsepower than normal, says Lawrence. THis is a real generalization, but the weaker your heads, the more you will like the smaller centers ( 106-108) the better the heads, and the higher the compression, the more it will like the wider centers ( 112-114)everything else falls somewhere in the middle( 108-110) Once you get close with the cam centerlines, it wont make much differance if you change it up or down by 2 degrees. Mechanical aspects like maximum torque, narrower powerband, higher cranking compression rate, efficient compression rate, effective EGR effect, and lower oil consumption rate increase the car engines efficiency and make it energy efficient. The second cam would have a rougher idle, produce more torque and would rev quicker. A 110-degree lobe separation angle means that the peak opening points of the intake and exhaust lobes are 110 degrees apart. Now its not shifting into 3rd and you are here. . But you always have a cam card with the engine. The lobe separation angle is the angle between the two camshaft lobes that act on the valves. 108* or narrower lobe separation angle (LSA) is "Narrow" and 114* or wider (up to 117* or 120* for stock cams) is "Wide" , with 110 to 112* being the "normal" hot-rod cam. 68 Mustang, 306, AFR 185\'s, CI cam, FPA\'s, Bigs 650 DP, T5Z, 9" w/4.33's. Simply put, the lobe separation angle (LSA) is a measurement of how the intake and exhaust lobes are phased with each other. A wide lobe seperation is not always better than a narrow one, or vise versa. Around 70 percent of muscle-car performance cams fall into this range. I have seen a dyno test where an engine using identical duration and lift made more peak power with a 112 LSA than a 110 LSA. O onovakind67 Registered Joined Dec 14, 2001 6,242 Posts After swimming through the entire article, I hope you are now well aware of the 102 vs 110 lobe separation angle. If the overlap phase occurs too early, it will create an overly rich condition in the exhaust port, severely decreasing the gas mileage. We do not stock profiles with 109 or 114 lobe centers. In the 106 LSA, the engine can reach the maximum torque, making the driving more efficient and saving energy. ( 2 ) Estimated Ship Date: Feb 23, 2023 (if ordered today) Drop Ship. It should still make close to 600hp and 600tq in my 512" stealth headed big block. Powerband serves a massive contribution to the acceleration car. Come here to talk with others who like to drive fast. Also present during testing was a set of 1 7/8-inch Kooks headers, Comp hydraulic roller lifters, and F-body oil pan. When boost or nitrous are introduced, and engine builders contemplate choices between single-, dual- or reverse-pattern camshafts then the discussion gets muchmore technical. Equipped with the 120-degree (LSA) cam, the hybrid stroker produced 570 hp at 6,200 rpm and 535 lb-ft of torque at 5,200 rpm. by Mr. P. Fri Dec 12, 2008 6:36 pm, Powered by phpBB Forum Software phpBB Limited, General engine tech -- Drag Racing to Circle Track. This is why the LS series, and many other modern engines, can make great power on top and bottom with wide LSA camshafts and why a plethora of factory cylinder heads are flowing near (or above) 300 cfm. If you look at any given cam catalog, you will find that the majority of street-oriented cams fall in this range. 4 Impaired episodic memory and semantic knowledge are common in TLE, although dysexecutive traits . I'm surprized at these questions as well as some of the replies. " Tight lobe separations, such as 108 or shorter, will cause the peak torque to build earlier in the RPM range and peak-out in a short amount of . Lucky for us, Brian Tooley Racing stepped up with a dual spring package that allowed us to safely run our 0.624-lift cam. indeed, expect low vacuum with anything lower than 110-ish. To reiterate another point, I realize that wider LSAs tend to broaden the power band, but for a car I would like to bracket race a bit, as well as enjoy on the street, I was told that a narrower LSA will help the car accelerate at a faster rate. Required fields are marked *. A cam card with its myriad numbers, acronyms, and abbreviations is one red-pen stroke away from a failed math test. kinda off topic.. but while we're on the topic of cams, duration,lift,ect has anybody heard of using high compreshion (13:1) on pump gas, by useing alot of duration? I had a 110 cam in my beetle and I didn't like it-the bottom end was doggy. We use 86b webcams with 1.25 rockers frequently in stroker motors.It's a nice way of getting close to .500" for hot street motors with average heads. LSA helps determine the cam's behavior; you can take a given set of lift and duration figures, change the LSA, and get cams with vastly different characteristics. Now here is where it gets tricky. When degreeing in the camshaft, you are making sure the intake centerline is precisely where the cam is intended to be. Most street cams are ground 4 degrees advanced which boosts bottom end, throttle response, vacume, mpg driveability etc. The tighter the lobe center, the lower the RPM range; the wider the lobe center, the higher the RPM range. Every spec is a road map to what the valves are doing, the most common of which are lift, duration, and lobe-separation angle (LSA)the latter needing the most explanation. The valve covers, valvetrain, intake manifold, harmonic balancer, front cover, timing set, and cam were yanked. 2023 Power Automedia. It's wet flow tested at 690cfm. dont sound like a verry street friendly motor butany thoughts? A few other major and, Read More Heres What Causes Your Car to Bog Down When AcceleratingContinue, Your email address will not be published. VerticalScope Inc., 111 Peter Street, Suite 600, Toronto, Ontario, M5V 2H1, Canada. After the next three pulls, it was clear the 113 cam was way down on low-end torque. that is why people running 112 or 114 lobe centres retard the cam ,that way the exhaust event is back were it was before .this helps in exhaust valve tempatures--anyway today i talked too barry who is the owner of shadbolt cams and we talked about cam lobe centres -he considers 108 centre quite narrow and for a very narrow power band operation ,with a 112 he figures with the carbs with straight & even runs at the valves there should be no noticable loss of low end power, a 112 lobe would be a great choice for a great street strip motor -better lower torque followed with a flatter rising torque curve as well as rpm range extended 500-700 rpm -. I don't think your duration figures are too outlandish and with the tight LCA and high lift, it should make some big torque.